I have a 2004 Silverado, 5.3 l. My #4 position on the fan switch keeps failing. Per advice, I replaced the blower motor resistor. After doing so it fixed the #4 position problem. A few days later, the #4 position quits working again. Thinking I may have received a bad resistor I ordered a new one and installed it. Same scenario. Workes for a couple of days then quits working. Am I barking up the wrong tree?
Thanks for any ideas...

 

I would check and make sure that the connector to the resistor pack is not charred/burned creating a poor electrical connection. You remove the plug, reconnect it and #4 works for a short time then stops working. Then you "disturb" the electrical connection, it works for a bit then stops. See where I am going?

Good Luck!

 

Thanks...I'll check it out.